It seems that we wouldn't be seeing Rudeus Greyrat for quite some time as the release date of the second part of the cour of Mushoku Tensei: Jobless Reincarnation has been pushed back for one whole anime season that instead of arriving this Summer, it would be back on Fall.
One of the best anime in the roster of last Winter season, Mushoku Tensei has introduced us to quite a spectacular isekai anime with tells the story of a recluse shut-in who gets a second chance in life after being reincarnated to a magical protegee in the fantasy Six-Faced world as Rudeus Greyrat.
Mushoku Tensei: Jobless Reincarnation has been confirmed to have a total of 23 episodes for the whole first season. The first part of the cour ended with Episode 11 last Winter anime season. If you're still confused which season it is in, it is still in its first, it just had a break, supposedly for 3 months but as confirmed by the show's team reported by comicbook.com, the break would be a little longer for 6 months and it is due to "various circumstances" that the release of the second part would be this Fall instead of its original schedule this Summer.
Based on the light novel of Rifujin na Magonote with the illustrations of Shirotaka which is published in Kadokawa's Media Factory with 22 volumes. The light novel also inspired to have a manga series by Yuka Fujikawa, Mushoku Tensei: Jobless Reincarnation had a global reach thanks to the streaming platforms of Funimation, Hulu, and Netflix Japan.
Mushoku Tensei: Jobless Reincarnation will return for the second cour with Episode 12 this October 2021 forming part of the Fall anime season.